let name = '余浩'
let age = 11
let flag = true

function sum(num1,num2) {
  return num1 + num2
}
if(flag){
  console.log(sum(90,80))
}
export {
  flag,sum
}

//直接导出
export let yuhao = 'sss'

//导出函数
export function aaa(){

}

//导出类
export class Person {
  aaa() {}
}

//export default  别人导入的时候可以自己起名字import yourname from "地址"
//只能有一个default 
const address = '北京'
export default address
